Water enters a 13-cm-diameter pipe steadily with a uniform velocity of 2 m/s and exits with the turbulent flow velocity distribution given by u = umax(1 − rR)1/7 . If the pressure drop along the pipe is 10 kPa, determine the viscous force exerted in the pipe by the water flow. Take the density of water to be 1000 kg/m3. The average velocity is equal to 0.816 times the max velocity. The viscous force exerted in the pipe by the water flow is 50

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]